A conventional filter for use in a reverse air pulse cleaning filter system is generally comprised of a conventional filtering medium having a housing therearound to support the filter medium, and is constructed and arranged to allow air to freely flow through the filter medium. The housing generally has a inner perforated core with an outer surrounding perforated exterior which are connected together at its base and top end by a base plate and top plate, respectively. The filter medium is disposed between the inner core and the exterior of the housing and is supported thereby. Generally, the filter medium is also connected to the base and top plates thereby creating a seal between such plates and the filter medium.
Generally, the air flow in a conventional filter flows from the exterior of the filter through the outer body of the housing, into the filter medium where the purifying of the air takes place, and then out through the perforated core of the filter housing. When cleaning of the system is desired, the direction of the air-flow is reversed and highly pressurized pulses of air are introduced into the core of the filter and are forced outwardly through the filter medium when the reverse jet air pulses come in contact with the base plate of the filter.
Generally, the reverse air pulses which are introduced into the filtering system are quite strong and can damage the internal structure of the filter. Conventional filters which are reverse air pulse cleaned often contain baffles or sleeves in the outputs of the filters where the reverse pulse is introduced to redirect the natural flow and force of the air pulse so that the filter medium will not be damaged thereby. Quite often the air flow is redirected away from the filter medium to an end plate at the end of the filter to avoid the direct contact of the filter medium.
However, portions of the filter structure other than the filter medium may also be damaged by the high pressure of the reverse pulse air cleaning. For example, the seal between the filter medium and the housing around the filter medium may be ruptured by the high force of the pressurized reverse air flow. This is particularly true when such filter systems direct the reverse air pulses towards the end plates of the filters where the filter medium is commonly connected to the housing.
Thus, there has been a long-felt need for a filter which will be constructed so as to prevent the impact of the pressurized reverse pulses of air which are introduced to clean the filter from damaging the filter medium or the seal between the filter medium and housing. The present invention offers a solution to this problem.